Custom gowns for pagent contests

[Vicwt]

Does anyone know if designers approached to do custom gowns for pagents, like Miss Virtual World, get paid?  Or do they do this custom work for exposure and then try to sell the gown later and make money off of it that way?  I know a lot of established designers get approached with this and I'm sure it's very time consuming.  I'm curious what's the going rate for one of those gown versus having something else custom made, like a wedding gown, which I have had done for me before.